A boy who saw the incident said that after Rikki was punched to the ground, he was kicked hard.

The young witness, who cannot be named, was giving evidence on a video link at the murder trial of Danny Scott and Jack Walton at Newcastle Crown Court.

He said: “There was some pushing and shoving and I saw a big kid move one of his friends out of the way and throw a punch at Rikki.

“I don’t think Rikki expected it. He looked up, then looked lifeless and just fell over. The lad who delivered the punch raised his arms up and went ‘Ha, I’ve just knocked your mate out’ and put his arms above his head like he was celebrating.

“When he was on the ground a few kicks were thrown. It was the way you would kick a football, full force like a volley.”

Scott’s barrister said his client accepts landing the punch but claims he was under threat of attack from Rikki at the time.

Scott and Walton are accused of killing the teenager following a fall-out at a Christmas disco because Rikki was winding up one of their friends by saying he looked like singer Justin Bieber.

When Scott and Walton’s group left a pub, Rikki chased after them and may have been angling for a fight, the court has heard.

But he ended up surrounded by three or four lads and prosecutors claim Scott floored him with a punch, then the group landed kicks and stamps on him.

Rikki, an apprentice heating engineer, of Allanville, Camperdown, had been drinking with friends at his local, The Halfway House, on December 23 last year.

He died four days later, after suffering massive head injuries which prosecutors say were caused by him hitting his head on the ground and then being stamped on.